Work holder



NOV. 2 192 BORDE K HOLDER Filed April 1925 TTORNEYS Fatented Nov. 2, 1926.

UNITED STATES BRADFORD BORDEN, OF CLEVELAND, OHIO.

WORK HOLDER.

Application filed April 4, 1925.

My invention relates to work holders and particularly, although not necessarily, to a work holder and centering device for use in connection with die stocks.

Briefly stated, the paramount objects of the invention are to provide a work holding and centering device which may be quickly and accurately set by sight or touch for work of different sizes whereby it may be ellicaciously used in a dark or poorly lighted shop; to avail of a novel, variably positionable means for positively limiting advancement of the device toward the work, which means is designed to frictionally restrain any tendency of the device to draw away from the work, means other than said retaining means serving to sustain the device; and generally to furnish a work holding and centering device which will be very simple in its construction, strong and durable, and inexpensive of manufacture.

The foregoing and other features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, reference should be had to the accompanying drawings in connection with the following descriptive matter, the drawings depicting what I now regard as a preferred embodiment of my inventive idea. It is to be understood, however, that I do not propose to limit myself to the exact construction shown in the drawings, and that I am aware that various changes'and modifications may be made without a departure from the invention as claimed.

In the drawings Figure 1 is an elevation of a die stock illustrating the practical application of my work holder;

Figure 2 is a sectional view through the work holder, and

Figure 3 is a sectional detail depicting a slight modification.

Figure f is a perspective view of the adjustable stop employed in the modified form of the invention shown in Figure 4.

Referring specifically to the drawings, the die stock'which I have chosen to illustrate for showing the application of my work holder is denoted generally by the numeral 5, it being of the type disclosed in my copending application Serial 718,090 which was filed on June 7, 1924. For present purposes it will suflice to say that the dies are Serial No. 20,795.

indicated at 5 and that the stock is slidable on posts 6 which are fastened in a rotatable plate 7 carried by the neck 8 of the body portion 8 of my improved work holder. In operation the teeth of the dies 5 bite into the work and cause movement of the die stock in the direction of the work holder.

The body portion of the work holder is shown as being cylindrical and is bored out as indicated at 8 co-aXially with the opening in the die stock into which the dies 5 project. The pipe or otherwork is presented to the dies through the work holder in the usual manner.

The member 8 has protruding from its outer periphery a plurality of radially arranged bosses 9 which are cored out as indicated at 9 to form a bore which communicates through a relatively reduced tapped opening 9 to the bore 8'? of the body portion.

The work engaging and centering members are designed to be received within the bosses 9, and such members include a relatively elongated screw threaded shank 10 formed integrally at its outer end with a cylindrical enlargement 11 having a plurality of circumferential grooves 12. The distance between each groove is proportional to the differences in the diameters of the various standard sizes of work for which the device is adapted and it is to be noted that the wall of each groove, which is nearest the threaded shank 10, is beveled as indicated at 11 while the other wall is perpendicular to the axis of the cylindrical portion 11. A finger grip 13 is formed at the outer end of the cylindrical enlargement 11 whereby the shank 10 may be rotated to take in the threaded opening 9 and to be projected into the work receiving bore 8 of the body portion. The diameter of the cylindrical portion 11 is such that it is slidingly received in the bore 9 of the boss 9.

Heretofore in using work engaging mem bers characterized by screw threads, considerable difficulty has been experienced in se curing an accurate setting of each of the plurality of members, it being obvious that in the absence of an accurate setting of each member, the work will not be held in the exact center of the work receiving opening and exactly concentric to the opening into which the dies 5 project. I hate illustrated two means for accurately setting the' work holders for standard sized pipes or other work. In Figures 1 and 2 each of the bosses tension at the outer end thereof, the outer portion of the bore of said boss being unthreaded to slidingly receive said extension, a plurality of spaced abutments formed upon said extension, and movable means selectively engageable with said abutments, said means upon advancement of said screw being brought to bear against the end of said boss whereby to constitute a stop, and the binding of said means against said abutments and end of said boss serving to irictionally resist the turning of said screw to retract the same.

4, A work holder for thread cutting tools comprising a body portion having a medial work receiving opening, said body portion having a plurality of tapped radially eX- tending openings communicating with said work receiving opening and relatively enlarged bores communicating with said tapped openings, work engaging member's threaded throughout a portion of their length and taking in said tapped openings, the unthreaded portion of said members being enlarged to slidingly tit said relatively enlarged bores, and means variably positionable to engage the unthreaded portion or" said members whereby to restrain the same against movement and whereby the said members may be accurately set to properly engage and center work of different sizes.

5. A work holder for thread cutting tools comprising a body portion having a medial work receiving opening, said body portion having a plurality of tapped radially extending openings communicating with said work receiving opening and relatively enlarged bores communicating with said tapped openings, work engaging members threaded throughout a portion of their length and taking in said tapped openings, the unthreaded portion of said members being enlarged to slidingly fit said relatively enlarged bores, said unthreaded portions having depressions cut therein, and means engageable in said depressions and adapted to abut against the body portion of said work holder when the work engaging members are advanced whereby to limit movement in the direction of the work, the abutting of said members against said body portionv effecting a binding thereof in said depressions whereby to restrain movement of said members as would disengage the same from set position against the work.

6. In a work holder for diestocks and the like, a tapped boss, a screw threaded member working in the tapped bore of said boss and having an unthreaded part at its outer end, the bore oi? said boss being unthreaded adjacent its outer end to receive the unthreaded portion of said member, the latter having a plurality of spaced circmnferential grooves therein, movable means selectively engageable with said grooves and designed upon advancement of said member in said boss to engage the end thereof and act as a stop for said member, and the binding of said means against the outermost wall of a groove and against the end of the boss, servmg to frictionally restrain said member against turning.

7. In a work holder, a tapped boss, a screw threaded member working in said boss and having a plurality of spaced circumferential grooves therein, means movable transversely of the axis of said member and selectively engageable in said grooves, said means upon engagement with the end of said boss constituting a stop for said member, and the binding of said means in said groove and against the end. of the boss serving to trictionall'y restrain the member against turning.

8. In a work holder, a tapped boss, a screw threaded member working in said boss and having a plurality of spaced circumferential grooves therein, means carried by said boss and yieldingly movable transversely of the axis of said member and selectively engageable in said grooves, said means upon engagement with the end of said boss constituting a stop for said member and the binding of said means in said groove and against the end of the boss serving to frictionally restrain the member against turning, and the wall of each groove nearest said boss being beveled substantially as and for the purpose set forth.

In testimony whereof I alfix my signature.

BRADFORD BORDEN. 

